Enhancing the thermal performance of a photovoltaic panel using nano-graphite/paraffin composite as phase change material

In this study, a nano-graphite/paraffin composite is used to augment the cooling performance of a PV panel, which significantly increases the output power due to decreasing the thermal stresses and current mismatching problems. The constructed composite is a phase change material (PCM). In order to retard the melting of PCM, a finned tube-heat exchanger is inserted inside the PCM. At first step, pure paraffin and finned tube-heat exchanger are used for cooling of a PV panel and secondly, graphite nanoparticles (ϕ = 0.002–0.012 (w/v)) are combined with PCM. The results of temperature, voltage–ampere curves and the maximum power output of the PV panel using PCMs are compared with no cooling device. Results show that using the nano-graphite/paraffin composite has significantly added benefits over using pure paraffin. By increase in water flow rate, the surface temperature of the PV panel is decreased because of increase in the heat transfer rate between the water and PCM around the tubes. Average surface temperature of the PV module is reduced from 336.15 to 310.25 K by using nano-graphite PCM with ϕ = 0.01 (w/v) and the highest value of water flow rate (Q = 100 mL s−1). The maximum enhancement in the power output of the PV/nano-PCM system by using the efficient conditions is 21.2%. The proposed system not only boosts considerably the output electrical power, but also reduces the PV panel temperature while keeping it uniform for each cell.